Also killed were Muhammad Ateeq-ur-Rehman, 18, and Nefessa Aziz, 35. Zaib-un-Nisa, 54, died in hospital a week later.

Three others escaped the inferno.

Mohammed was released after questioning and jumped bail. He was believed to have fled to Pakistan but could be back in Britain.

During the police visits a number of people originally interviewed were spoken to again.

Police have also produced a digitally-aged image of what Mohammed may look like today, aged 31.

Det Supt Lisa Griffin, of West Yorkshire Police’s Homicide and Major Enquiry Team, said: “We are following a number of new lines of enquiry following the day of action and I want to thank residents of Huddersfield for the fantastic response we have had so far.

“Responses to our Bluetooth messages and tweets have also been positive and we are now also following up information received in reply to the messages.”

She added: “I want to emphasise again that West Yorkshire Police remain utterly committed to locating Shahid Mohammed and seeking justice for Mr Abdul Chishti and his family.”

Anyone with information should contact police on 01274 373737 or anonymously via Crimestoppers on 0800 555 111 or email wypenq1@gmail.com